The present invention relates to a vehicle window opening device such as a power window device installed in a vehicle.
Japanese Laid-Open Patent Publication No. 2011-122369 discloses an example of a conventional vehicle window opening device (power window device) that includes an anti-drawing function, which limits situations in which an object is drawn into a door when opening a vehicle window. Such a vehicle window opening device detects an object that is drawn into a door by an opening vehicle window based on characteristic values (e.g., transition of changes in rotation speed) of the motor, which functions as a drive source. Based on the detection result, the vehicle window opening device, for example, deactivates the motor.
However, when the above vehicle window opening device starts operating, the characteristic values of the motor may be unstable because of a backlash in a drive system including the motor and the like. This may cause erroneous detection of a drawn-in object, that is, detection of a drawn-in object even though such a situation has not actually occurred. To solve this problem, a mask zone that invalidates the anti-drawing function may be set to a predetermined zone from where the window starts to open. In this case, the length set for the mask zone needs to be considered.
Additionally, when opening a fully closed vehicle window, the vehicle window opening device is affected by the friction produced with a weather strip arranged on an upper window frame in addition to the backlash in the drive system. Thus, when opening a fully closed vehicle window, a longer zone is needed between where the operation is started and where the characteristic values of the motor are stabilized than when opening the vehicle window that is not fully closed. Accordingly, a longer mask zone needs to be set to allow for application to a situation in which opening the fully closed vehicle window is opened. However, when the length of the mask zone is set in accordance with the fully closed state, the mask zone is longer than necessary when starting to operate the vehicle window from a non-fully closed state. This adversely affects the drawing detection function.
Japanese Laid-Open Patent Publication No. 2010-144379 describes another example of a conventional vehicle window opening device that performs speed control to obtain a low speed zone in which a vehicle window is operated at a low speed and a high speed zone in which the vehicle window is operated at a speed higher than the low speed.
The object detection function (entrapment detection function and drawing detection function) may be applied to a vehicle window opening device that performs speed control such as that described above. However, the change in the motor rotation speed would be small when an object interrupts the operation of the vehicle window in the low speed zone, in which the speed of the vehicle window is low. This may lengthen the time used to determine object detection.
Additionally, in a vehicle window opening device such as that described in Japanese Laid-Open Patent Publication No. 2011-122369, when closing the vehicle door during the opening of the vehicle window, an impact produced by the closed door increases changes in the characteristic values of the motor. This may cause an erroneous detection of a drawn-in object. An erroneous drawn-in object detection would result in an erroneous operation, that is, execution of the anti-drawing control (e.g., deactivation of motor) when an object has not been actually drawn.